Abstract

The Schwarzburg anticline exposes late Precambrian basement of northwestern Saxo-Thuringia (Central European Variscides). The overprinting relations of fabric elements and the geologic frame of the Neoproterozoic clastic rocks reveal three deformation phases: D1 - compression, D2 - extension, D3 - compression. The D3-compression is related to the Variscan orogeny and resulted in lower greenschist facies south-east directed thrust contraction between ⁓ 330 and 310 Ma. D3-shearing occurred more or less parallel with the S1-foliation. Within the central structural unit, S1 has been affected by tight and disharmonious folding. The S1-foliation is separated from the D3-structures by Late Cambrian to Tremadocian dyke intrusions and associated extensional features (D2). The deformation-phases of the late Precambrian basement apparently correlate to the formation of late Precambrian basement at the periphery of Gondwana (D1, ⁓ 540 Ma), early Palaeozoic crustal extension and the separation of terranes (D2, ⁓ 490 Ma) and the Carboniferous collision at the north-western boundary of Saxo-Thuringia (D3, ⁓ 330 Ma)